While the prior-art buckle folding machines of this class are usually used to fold sheets of paper passing through one by one, devices for collecting and folding sheets of paper are also known, in which a plurality of sheets of paper are collected in a collection station that is provided with an electronic sheet counting device presettable to different count values, and they are subsequently folded together in a folding mechanism provided with at least one folding roller pair and one folding blade.
Such devices are used, among other things, to jointly fold sheets of paper which are fed in from, e.g., a printing press and contain related information, and then to subsequently feed them to another processing station, e.g., an enveloping machine, for further processing.
In these prior-art devices, the collection station is arranged directly next to a folding machine, and the folding machine usually has an intake device for taking in together the sheets of paper collected in the collection station. One peculiarity of such a folding machine is that besides the folding pockets, it has, in front of each folding site, a folding blade or sword, by which the sheets are deflected together into the corresponding folding site for fold formation. Folding machines with such folding blades have been known from, e.g., DE 3,840,856 A 1 or DE 3,830,656 C 1.
Another peculiarity linked with a folding machine using such a collection station is that at least one folding roller of one folding roller pair is mounted elastically in relation to the other and/or can be set to different distances to permit correspondingly different folding gap widths to be set for folding a plurality of sheets or a plurality of sheet layers.
However, buckle folding machines of this class, whose folding rollers are provided with an elastic jacket and in which it is therefore possible not to use a radially elastic mounting of the folding rollers, have been known as well (see U.S. Pat. No. 3,788,638). However, more accurate folding can be achieved, in the case of the simultaneous folding of a plurality of sheets of paper, with radially elastically mounted folding rollers that can be adjusted to defined folding gap widths.